PF Cont. on above 15000

Dear Experts,

One of my employees basic salary is shown as 20,000 in epf portal. He wants to contribute on 20000 of Rs 2400.
But I, the employer, will contribute 1800 only.
My query, is it possible to contribute 2400 from employee and 1800 from employer?

If possible, is there any different process to file ecr?

Pls help.